TM::Synchronizable(3) Topic Maps, trait for storing objects into backends


my $tm = .... # get a topic map from somewhere
use Class::Trait;
Class::Trait->apply ($tm, "TM::ObjectAble");
my %store; # find yourself a proper store, can be anything HASHish
# append it to the list of stores, or ....
push @{ $tm->storages }, \%store;
# prepend it to the list of stores
unshift @{ $tm->storages }, \%store;
# store it (the proper storage will take it)
$tm->objectify ('tm:some-topic', "whatever object or data");
# get it back
my @objects = $tm->object ('tm:some-topic', 'tm:some-topic2');
# get rid of it
$tm->deobjectify ('tm:some-topic');


This trait implements functionality to store arbitrary data on a per-topic basis.

Conceptually, the storage can be thought as one large hash, as keys being use the internal topic identifiers, as values the object data. But to allow different topics to store their object data in different places, this interface works with a list of such hashes. Each hash (native or tied to some implementation) in the list is visited (starting from the start of the list) and can take over the storage. Whether this is based on the topic id, on some other topic information, or on the MIME type of the data (if it has one), is up to the implementation to decide.



$listref = $tm->storages

This method returns an array reference. You can "unshift" or "push" your storage implementation onto this list.


    my %store1;
    push @{ $tm->storages }, \%store1
$tm->objectify ($tid => $some_data, ...);

This method stores actually the data. It takes a hash, with the topic id as keys and according values and tries to find for each of the pairs an appropriate storage. If none can be found, it will raise an exception.

NOTE: Yes, this is a stupid name.

$tm->deobjectify ($tid, ...)

This method removes any data stored for the provided topic(s). If no data can be found in the appropriate storage, an exception will be raised.

@objects = $tm->object ($tid, ...)

This method returns any data stored for the provided objects. If no data can be found for a particular topic, then "undef" will be returned.


Copyright 20(10), Robert Barta <[email protected]>, All rights reserved.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.